About PDFSignatureValidator

PDFSignatureValidator is a free online tool that lets anyone check whether the digital signatures in a PDF are valid, and whether a document has been altered since it was signed. It works for Aadhaar e-PDFs, GST certificates, government-issued documents, eSign files and corporate or contract PDFs.

Why we built it

Millions of people in India and around the world receive digitally signed PDFs every day, but verifying them is confusing. Many PDF readers show a question mark on documents whose signature is cryptographically intact, and the existing online checkers ask you to upload sensitive files to a server you cannot see. We wanted a tool that is both accurate and completely private.

PDFSignatureValidator is an independent technical utility built on open standards such as PDF, X.509 certificates, PKCS#7 / CMS, OCSP and CRL. It does not use or claim any proprietary Adobe technology, and it is not affiliated with, endorsed by, certified by, or approved by Adobe, UIDAI, any government agency, or any certifying authority. Validation results are technical findings, not legal advice or an official verification service.

Privacy by architecture

PDFSignatureValidator never uploads your file. Every signature is verified inside your own browser using the WebCrypto API. There is no server that receives the document, so there is nothing to store, leak, or log. You can confirm this yourself by opening your browser's network inspector while you validate a file, you will see no upload request.

How it works

The tool extracts each signature from the PDF, recomputes the document hash, verifies the cryptographic signature against the signer's certificate, parses the certificate details, and evaluates the trust chain. It then presents a clear report with an overall status and a breakdown of every signature in the file.

Have feedback or a feature request? Visit our contact page.